<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>作业1</title>
</head>
<body>
<script>
  function getMax(a,b,c){
    return a>b?((a>c)?a:c):(b>c?b:c);
  }
  let max = getMax(13,12,20);
  document.write("max="+max);
</script>
</body>
</html>